Hello,
I have a problem with my SPARC machine (Netra X1).
I'm fairly sure the problem was caused by a glibc upgrade (2.22-r4 -> 2.23-r3). That is, I upgraded every other package, I rebooted and upgraded glibc. The last thing I could see (I was using a tmux session) was the message "safely unmerging existing instance" (or whatever text emerge prints in this case). At that point I could not issue any command in the tmux session, and neither open a shell over SSH. I suspect there was a memory leak which saturated the swapfile.
Then I hard rebooted.
At this point, after the kernel is loaded, I get a out-of-memory kernel panic. At first it was something related to "loadkeys", so I rebooted with "init=/bin/sh" and removed "keymaps" from the boot runlevel. Now I have a similar problem with mount. Attached is the complete log from when I power on the machine (lines like --> [NNN lines] mean that the previous line was repeated NNN times).

Any idea on what could have been the problem? I had a similar issue few years ago when after a glibc upgrade every binary dynamically linked to it failed and had to throw away my installation and start from scratch, but this time if I boot with "init=/bin/sh" I can run commands.

If I manually mount my filesystems and unmount /dev and mount /proc I can run emerge. However, I then get an out-of-memory kernel panic.

I have a cross compiler and emerge, so I could create a new installation, but I'm not sure if I'll be able to merge the packages.